Electrical connector for printed circuit board



July 19, 1966 w` A. GAMMEL, 5R 3,262,082

INVENTORS WALTER A. GAMMEL SR.

ATTORNEYS United States Patent'O 3,262,082 ELECTRICAL CONNECTQR FOR PRINTED CIRCUIT BOARD Walter A. Gammel, Sr., Minneapolis, Minn., assignor, by

mcsne assignments, to G. T. Schjeldahl Company, a

corporation of Minnesota Filed Oct. 10, 1963, Ser. No. 315,194 9 Claims. (Cl. 339-17) The herein-disclosed invention relates to miniature electrical connectors and has for an object to provide connectors having diiferent numbers of contacts and different arrangements of parts from molded stock utilizing a minimum number of molds.

Another object of the invention resides in providing stock of lengths suitable for making the maximum number of contacts and cutting off the stock to lengths suitable for supplying connectors having a lesser number of contacts than the maximum.

A still further object of the invention resides in forming the contacts with lugs adapted to be bent into hook form for permanent connection to the body members with which they are used or which may be projected outwardly therefrom to permit of welding or soldering.

An object of the invention resides in providing a construction in which ribbon-type contactsof uniform width and thickness may be used land in further providing locking means engageable with each contact for restraining movement of the same relative to the body of the connector in the direction of its length.

Another object of the invent-ion resides in constructing certain of the body members with elongated grooves and certain of the body members with keys adapted to tit into said grooves and in lfurther yforming the contacts with offsets adapted to be received in said grooves and held in position by said keys.

Other objects of the invention reside in the novel coustruction and arrangement of .parts and in the details of construction hereinafter illustrated and/or described.

In :the drawings all of the views are drawn to enlarged scales.

FIG. 1 is a plan view of an assembled connector constructed in accordance with the invention.

FIG. 2 is an elevational view of the structure shown in FIG. 1 with a part cut away.

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 1.

FIG. 4 is .a perspective view of the body members of the connector.

FIG. 5 is a perspective view of the core member of the connector.

FIG. 6 is a fragmentary perspective view of a gang of contacts prior to bending of the same into form for assembly.

FIG. 7 is a perspective view of one of the contacts of the connector fully formed, detached and ready for assembly.

FIG. 8 is a perspective view of a portion of a printed circuit board adapted to be used with the invention.

FIG. 9 is a sectional view showing the method of using the circuit board shown in FIG. 8.

The electrical connector embodying the instant invention consists of two spaced lbody members 10 and 11 and a core therebetween. These parts are molded from a suitable plastic material having insulating properties .and which may be readily sawn or machined. A phenol-formaldehyde composition or some similar composition may be used. Between these parts are disposed a number of contacts designated by the reference numerals 60 which lare adapted to connect with the terminals of printed circuit boards or cables. These parts will now be described in detail.

zz Patented July i9, 1956 The body members 10 and 11 are identical in size and construction and are made from a molded ybody stock cast in lengths suitable for the manufacture of connectors having a desired maximum number of contacts. The body members 10v and 11 being the same only the body member 10 will be described which is shown in detail in FIG. 5. The body member 10 is substantially rectangular in cross section having an inner surface 13, an outer surface 14 and Ilateral edges 15 and 16. Extending outwardly from the surface 13 of the tbody member 110 .is an elongated key strip 17 which lies parallel with the inner and outer surfaces 13 and 14 and the lateral edges 15 and 116 of the body member 10. This key strip is disposed closer to the edge 116 than to the edge 15. Formed in the surface 13 of the body member 1t) are a number of transverse grooves `18 which are of a width great enough to receive the contacts and of substantially the same depth as the thickness of said contacts. The grooves l18 extend up to the key strip 17 and through the la-teral edge 15 of the body member. On the other side of the key strip 17 are formed in the surface 13 grooves 19 which are of `the same width yand depth as the grooves 18 and which lie in continuation thereof. Grooves -21 extend across the upper end of the body member 10 and into the surface of edge 15 and Iterminate in pockets 22 extending through said edge and into the body member at a locality adjacent the surface 14 of said body member.

The core 30 is also made from a stock molding and is constructed asshown in FIG. 4. This core consists of two end pieces 32 and 33 and a bar 34 disposed at the lower ends of said end pieces and connected to the same. The end pieces 32 and 33 are identical in form and only the end Ipiece 32 will be described. This end piece is rectangular in cross section having 'lateral s-unfaces 35, 36, 37 and 38 ,and end surfaces 39 and 41. The bar 34 issues from the surface 36 of the end piece 32 `at the lower portion of the same. A spacer 42 is formed on the surface 36 of said end piece which extends from the bar 34 to the surface 39 and lies midway between the surface-s 37 and 38. This spacer engages the ends of the body members 10 and 11 and holds the same in proper assembled relation. Holes 43, 44 `and 45 are drilled through the end pieces 32 and 33 Iand through which bolts may be directed for the purpose of attaching the connector :to a printed circuit board or other structure to which it is to be attached.

The connecting bar 34 as stated extends between the end pieces 32 and 33 at the lower ends thereof. rThis bar is substantially rectangular in cross sec-tion and has surfaces 46, 47, 48 4and 49. The Width of the bar from surface 4S to 49 is equal to the width of the spacer 42 and the surfaces formed thereby are planiform and engage the surfaces 13 and l14 of the body members 10 and 11 when the parts are assembled. The bar 34 has keyways 51 formed on opposite lsides thereof and which extend into the surf-aces 48 and 49 and are parallel with said surfaces and the surfaces 46 and 4'7. These keyways are adapted to receive the key strips 17 formed on the body members 10 and 1|1 and are a little lar-ger than said key strips to receive portions of the contacts 6i) therebetween as will be presently more fully explained.

The stock from which the core 3i) is constructed may be made of :a single length with one end piece molded thereon and having a bar of a length sufcient, when assembled with an identical companion bar, to receive the maximum number of contacts. In such case the bars are cut olf, :and preferably on a bias to form a diagonal joint 50 therebetween and to a length suicient to receive the desired number of contacts between the end pieces 32 and 33. A mold for such construction would have one end piece and a bar somewhat longer than re- Si quired to support one half the maximum number of contacts and thus requiring two castings for each connector. Or the casting may be made to provide both end pieces with a bar therebetween long enough to support the maximum number of contacts and then cutting off the bar on a diagonal to make the composite bar of the right length to make the device of siutable capacity to hold the desired number of contacts.

The contacts 60, one of which is shown in FIG. 6, are constructed of strip material and are substantially uniform in width throughout. The particular contact shown comprises a shank 61 which has issuing from it a portion 62 vadapted to make contact with the contact of the device with which the connector is to be used. Portion 62 has two humps 63 formed on the same and by means of which positive contact is made with the cooperating contact or terminal. The shank 61 further has formed in it a rectangular offset 64 which snugly tits into the key- Way 51 in the bar 34 of core 30. This offset also receives the key strip 17 and when the parts are secured together serves as a key which holds the contact from longitudinal movement. The extreme end of the shank 6l forms a soldering lug 65 which lies in continuation of said shank. A hole 66 in the end of said lug may be used for assisting in holding wire terminals attached to the lug when the parts are assembled and the contacts are being soldered.

The other end 67 of the contact 6G extends outwardly from the portion 62 and is disposed at right angles to the shank 6l. This portion of the contact is received in one of the grooves 21 of the body member with which it is used. The extreme tip 66 of the end 67 may be bent over to form a hook adapted to be received in the pocket 22 of the body member and when disposed therein assists in holding the portion 62 in proper position to be engaged with the contact with which it is associated.

The contacts 6l? may be made from strip material and formed and cut olf from the strip as the same are fabricated. Or if desired, a number of the contacts may be made as a gang 70 as shown in FIG. 6 in which the individual contact blanks 7l are spaced from one another by slots 74 and connected together at their ends by means of ties 72 and 73. Such a gang may be made by etching out the slots between the blanks '71 or by stamping out the intervening parts in a punch press. The gang so formed is bent and formed in a punch press to simultaneously perform the various operations on all of the blanks.

The assembly of parts is as follows: Adhesive is applied to the overlying portions of the body member and core and particularly at the localities of the key strips and keyways. The contacts 60 are then assembled in the grooves 1S and 19 with the key strips 17 received in the keys 64, with the portions 67 received in grooves 21, the hooks 68 received in pockets 22, with the Shanks 61 in grooves 19 and the soldering lugs 65 projecting outwardly therefrom. The parts are then clamped together and the adhesive caused to set. With the parts so arranged a socket 23 is formed in the assembled structure in which all of the portions 62 of the contacts 60 are disposed.

For use with the form of the invention shown in FIG. 9 a printed circuit board 80 may be used, a portion of which is shown in FIG. 8. This construction utilizes an insulating board 82 of a width and thickness to t into the socket 23 and has mounted on it the various components of the circuit. In addition, conductors 83 are employed attached to board S2 and which terminate in contacts 84 adapted to engage the portions 62 of contacts 60. Portions of the conductors S3 disposed inwardly of the contacts 84 are severed from asid conductors and raised therefrom to form soldering lugs 85.

If desired the hooks 68 may be omitted. In such case the hooks lie in continuation of the ends 67 and project outwardly therefrom as shown in FIG. 9 and serve as soldering lugs. The circuit board shown in FIG. 8 may be used with this form of the invention. The board is inserted into the socket 23 formed between the two sets of blades, each contact 84 of the board engaging the blade of one of the contacts mounted in the connector. When so disposed, the soldering lug 85 of one of the terminals 83 lies adjacent the soldering lug formed by the end 67 of one of the contacts 60 and the extreme tips of said soldering lugs may be welded or soldered together, -making a permanent connection. If desired to remove the board all of the soldered tips may be cut olf and the board pulled away from the connector. After the desired changes have been made in the circuitry the parts may be reassembled :and the lugs again soldered together. By making the lugs long enough, the procedure may be repeated as often as desired.

The advantages of the invention are manifest. With the particular construction disclosed a mold can be made for the core and another mold for the body members. These molds can be made to incorporate the desired maximum number of conta-cts. If a connector is desired having less contacts the members may be cut down to the required number of grooves and the members tted together accordingly. By means of the structure disclosed, a minimum number of molds is required. The instant invention provides an extremely compact connector and the contacts can be closely spaced. The pitch of the contacts can be as little as .025 inch. Where the form of the invention shown in FIG. 2 is employed stacks of contacts with boards attached may be utilized and the contacts caused to rest one upon the other. When so stacked there is no shorting of the :contacts of one connector with those of another connector. By means of the end pieces on the core of the connector the connector may be mounted in a direction parallel to the board or in a direction at right angles thereto. With the construction shown in FIG. 8 the contacts can .be used while determining the proper components on the board and after the components have been selected the soldering lugs may be soldered or welded together at their tips, thus making a permanent connection between the conductors and the contacts. If thereafter it should become desirable to open up the circuits and remove the board this can be accomplished by snipping off the soldered ends of the soldering lugs. With the lugs soldered or welded, connections remain permanent even when the connector is subjected to vibration. If desired, the invention may be utilized with various thicknesses of'board and the soldering lugs may be connected to flat conductor cable down to live mils.

Changes in the specific form of the invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of the invention.

Having described the invention, what is claimed as new and desired to be protected by Letters Patent is:

l. In a combination with an electrical connector having a socket and a contact therein and means serving as a plug having a terminal for engagement with said contact upon relative movement in a certain direction be tween said connector and said plug and toward one another,

a lug on said plug extending outwardly from said terminal in a direction normal to the direction of movement between said plug and connector and having a free end thereon,

a lug issuing outwardly from said contact and extending in the same direction as said first named lug and having a free end lying adjacent the free end of said first named lug when said socket and said plug are assembled, and

a fused joint between said lugs only at the free ends thereof.

2. In combination with an electrical connector having a socket and a contact therein and means serving as a plug having a terminal for engagement with said contact upon relative movement in a certain direction between said connector and said plug and toward one another,

a lug on said plug extending outwardly from said terminal in a direction normal to the direction of movement between said plug and connector and having a free end thereon,

a lug issuing outwardly from said contact and lying in juxtaposition with reference to said first named lug and having a free end lying adjacent the free end of said first named lug when said socket and said plug are assembled,

said lugs being flat and parallel and a fused joint between said lugs only at the free ends lthereof.

3. In combination with a planiform circuit board having a terminal on one face thereof and located at an edge of said board and a connector having a socket for the reception of said edge and a contact for engagement with said terminal upon relative movement of said board and connector in a direction in the plane of the board and toward one another,

a lug on said board extending outwardly from said board and normal thereto and connected to said terminal, said lug having a free end thereon,

a lug issuing outwardly from said contact and lying in juxtaposition with reference to said first named lug and having a free end thereon adjacent the free end of said first named lug when said board and said connector are assembled,

a fused joint between said lugs only at the free ends thereof.

4. In combination with a planiform circuit board having a terminal on one face thereof and located at an edge of said board and a connector having a socket for the reception of said edge and a contact for engagement with said terminal upon relative movement of said board and connector in a direction in the plane of the board and toward one another,

a lug on said board extending outwardly from said board and integral with said terminal, said lug being normal to said board and having a free end thereon,

a lug issuing outwardly from the end of said contact and lying in close proximity to and parallel with said first named lug and having a free end'thereon adjacent the free end of said first named lug when said board and said connector are assembled, and

a fused joint between said lugs only at the free ends thereof.

5. An electrical connector comprising:

an elongated body member,

a second elongated body member spaced from said first named body member,

an elongated core member disposed between said body members,

said members being constructed of an insulating material,

said body members having elongated surfaces and said core having elongated surfaces disposed adjacent the denoted surfaces of said body members to form pairs of facing surfaces between each body member and said core member,

said core member being of lesser width than said body members to form between said body members an inwardly directed groove extending along corresponding edges of said body members and serving as a socket,

said body members having a plurality of .transverse parallel grooves on the denoted surfaces thereof communicating with said socket and extending through the edge thereof opposite said socket,

a plurality of contacts, strip-like in form received in said grooves and disposed between said members and having portions entering said socket and lugs extending outwardly beyond said members and end pieces on said core member and extending across the ends of the body members and closing the ends of said socket.

6. An electrical connector comprising,

an elongated body member,

a second elongated body member spaced from said first named body member,

an elongated core member disposed between said body members,

said members being constructed of an insulating material,

said body members having elongated surfaces and said core having elongated surfaces disposed adjacent the denoted surfaces of said body members to form pairs of facing surfaces between each body member and said core member,

said core member being of lesser width than said body members to form between said body members an inwardly directed groove extending along corresponding edges of said body members and serving as a socket,

said body members having a plurality of transverse parallel grooves extending through the denoted surfaces thereof communicating with said socket and extending through the edges ythereof opposite said socket, c

a plurality of contacts, strip-like in form received in said grooves and disposed between said members and having portions entering said socket and lugs extending outwardly beyond said members,

end pieces on said core member and extending across the ends of the body members and closing the ends of said socket,

said body members being formed from body stock of a length suiicient to provide the requisite number of grooves to receive the desired number of contacts,

said core member being constructed in halves each containing an end piece overlying one end of each of the body members and a junction between said core sections disposed between said body members.

7. An electrical connector comprising,

an elongated body member,

a second elongated body member spaced from said tirst named body member,

an elongated core member disposed between said body members,

said members being constructed of an insulating material of characteristics permitting of cutting said members into predetermined lengths,

said body members having elongated surfaces and said core having elongated surfaces disposed adjacent the denoted surfaces of said body members to form pairs of facing surta-ces between each body member and said core member,

said core member being of lesser width than said body members to form between said body members an inwardly directed groove extending along corresponding edges of said body members and serving as a socket,

said body members having a plural-ity of transverse parallel grooves extending .through Kthe denoted surfaces through the edges thereof opposite said socket,

a plurality of contacts, strip-like in form received in said grooves and disposed between said members and having portions entering said socket and lugs extending outwardly beyond said members,

end pieces on said core member and extending across the ends of the body members and closing the ends of said sockets,

said body members being of a length suicient to provide the requisite number of grooves to receive the desired number of contacts,

said core member being constructed in halves each containing an end piece overlying one end of each of the body members and a core section,

a junction between said core sections disposed between said body members,

said core section having facing end surfaces disposed at an angle of substantially 45 degrees with reference to the direction of extent of said members.

8. An electrical -connector comprising,

an elongated body member,

a second elongatedbody member spaced from said first named body member,

an elongated core member disposed between said body members,

said members being constructed of an insulating material,

said body members having elongated surfaces and said core having elongated surfaces disposed adjacent the denoted surfaces of said body members to form pairs of facing surfaces between each body member and said core member,

said core member being of lesser Width than said body members to formbetween said body members an inwardly directed groove extending along corresponding edges of said body members and serving as a socket,

said body member having a plurality of transverse parallel grooves on the denoted side thereof communicating with said socket and extending Ithrough the edge thereof opposite said socket, and

a plurality of contacts strip-like in form received in said grooves between said members and having portions entering said socket and lugs extending outwardly beyond said members.

9. An electrical connector comprising,

an elongated body member,

a second elongated-body member spaced from said first named body member,

anelongated core member disposed between said body members,

said body members having elongated surfaces and said core having elongated surfaces disposed adjacent the denoted surfaces of said body members to form 5 3 pairs of facing surfaces between each body member and said core member,

` said core member being of lesser Width than said body said body members having a plurality of transverse parallel grooves on the denoted side thereof communicating with said socket and extending through lthe edge thereof opposite said socket,

a plurality of contacts strip-like in form received in said grooves between said members and having portions entering said socket and lugs extending outwardly beyond said members,

pockets formed along the edges of saidv body members adjacent said socket and hooks formed on said portions and extending into said pockets.

References Cited by the Examiner UNITED STATES PATENTS 2,699,534 1/1955 Klostermann 339--193 2,845,516 7/1958 Jones 339-275X 2,884,613 4/1959 Chandler et al. 339-198 2,999,997 9/1961 Tuchel 339--17 3,034,091 5/1962 Gluck 339-17 X 3,085,139 4/1963 Wright 339-17X 3,089,114 5/1963 Cole et al. 339--176 3,101,231 8/1963 Klostermann 339-176 3,196,377 7/1965 Minich 339--17 FOREIGN PATENTS 843,077 8/1960 Great Britain.

OTHER REFERENCES Gorn, Electrical Design News, April 1958, page 15, 339-17 (LM).

EDWARD C. ALLEN, Primary Examiner. ALFRED s. TRASK, Examiner. 

1. IN A COMBINATION WITH AN ELECTRICAL CONNECTOR HAVING A SOCKET AND A CONTACT THEREIN AND MEANS SERVING AS A PLUG HAVING A TERMINAL FOR ENGAGEMENT WITH SAID CONTACT UPON RELATIVE MOVEMENT IN A CERTAIN DIRECTION BETWEEN SAID CONNECTOR AND SAID PLUG AND TOWARD ONE ANOTHER, A LUG ON SAID PLUG EXTENDING OUTWARDLY FROM SAID TERMINAL IN A DIRECTION NORMAL TO THE DIRECTION OF MOVEMENT BETWEEN SAID PLUG AND CONNECTOR AND HAVING A FREE END THEREON, A LUG ISSUING OUTWARDLY FROM SAID CONTACT AND EXTENDING IN THE SAME DIRECTION AS SAID FIRST NAMED LUG AND HAVING A FREE END LYING ADJACENT THE FREE END OF SAID FIRST NAMED LUG WHEN SAID SOCKET AND SAID PLUG ARE ASSEMBLED, AND A FUSED JOINT BETWEEN SAID LUGS ONLY AT THE FREE ENDS THEREOF. 